This invention relates to a method for recording/reproduction by a recording/reproducing system for a visual inspection device. This invention is so designed that the recording/reproducing system for a visual inspection device can be produced at a low cost, and the time required for inspection can be shortened.
FIG. 7 shows the construction of a conventional tunnel wall surface inspection device. This tunnel wall surface inspection device is intended to perform the surface inspection of a long structure, such as a tunnel wall surface, with a high accuracy (a fine image resolving power).
As shown in FIG. 7, a line sensor camera 02 is installed on a vehicle 01 of the tunnel wall surface inspection device. The line sensor camera 02 shoots a tunnel wall surface T when the vehicle 01 is traveling. With the line sensor camera 02, single shooting gives an image only as one line (line image). However, the line sensor camera 02 takes pictures continuously while moving in a direction perpendicular to the direction of arrangement of pixels of the line sensor camera 02. By arranging the resulting line images in the moving direction of the line sensor camera 02, a plane image elongated in a band form in the moving direction can be obtained. Thus, the use of the line sensor camera 02 enables images to be shot with a fine image resolving power.
The vehicle 01 is also equipped with an odometer 03, which measures a distance traveled by the vehicle 01. Data on the traveled distance detected is recorded so as to overlap at the front of the line image data.
A recording system 04 is also mounted on the vehicle 01. The recording system 04 is composed of an A/D converter 05, a hard disk 06, and an MO recording unit 07.
The line image (overlappedby the traveled distance data; the same will hold in the following description) obtained by the line sensor camera 02 is converted by the A/D converter O5 from an analog signal to a digital signal, and stored in the hard disk 06. When the distance inspected is long, the amount of the image data is so huge that the capacity of the hard disk 06 needs to be large. The image data stored in the hard disk 06 is transferred to an MO disk 08 by the MO recording unit 07, where necessary.
At a place apart from the spot of inspection (the site where the tunnel wall surface inspection device is running), e.g., at a laboratory, an MO reproducing apparatus 09 and an image processor 010 are disposed. Thus, the image data are transferred from the hard disk 06 to the MO disk 08 on the spot of inspection. The MO disk 08 having records of the transferred data is carried from the spot of inspection to the laboratory or the like, where the image data are reproduced by the MO reproducing apparatus 09. The reproduced data are processed by the image processor 010, thus permitting the state of the tunnel wall surface T to be inspected and observed as images.
With the foregoing earlier technology, however, when the distance inspected is long, an immense capacity is needed for the hard disk 06. This makes the hard disk 06 expensive, eventually making the price of the entire device very high.
If the acquired data is carried around, it is necessary to transfer the image data from the hard disk 06 to a recording medium such as the MO disk 08. The transfer and carriage require several times the duration of measurement, causing inconvenience.